This repository has been archived by the owner on Jul 2, 2024. It is now read-only.
-
Notifications
You must be signed in to change notification settings - Fork 43
/
idle-callback-polyfills.mjs
81 lines (70 loc) · 2.21 KB
/
idle-callback-polyfills.mjs
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
/*
* Copyright 2018 Google Inc. All Rights Reserved.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
import {now} from './lib/now.mjs';
const supportsRequestIdleCallback_ = typeof requestIdleCallback === 'function';
/**
* A minimal shim of the native IdleDeadline class.
*/
class IdleDeadline {
/** @param {number} initTime */
constructor(initTime) {
this.initTime_ = initTime;
}
/** @return {boolean} */
get didTimeout() {
return false;
}
/** @return {number} */
timeRemaining() {
return Math.max(0, 50 - (now() - this.initTime_));
}
}
/**
* A minimal shim for the requestIdleCallback function. This accepts a
* callback function and runs it at the next idle period, passing in an
* object with a `timeRemaining()` method.
* @private
* @param {!Function} callback
* @return {number}
*/
const requestIdleCallbackShim = (callback) => {
const deadline = new IdleDeadline(now());
return setTimeout(() => callback(deadline), 0);
};
/**
* A minimal shim for the cancelIdleCallback function. This accepts a
* handle identifying the idle callback to cancel.
* @private
* @param {number|null} handle
*/
const cancelIdleCallbackShim = (handle) => {
clearTimeout(handle);
};
/**
* The native `requestIdleCallback()` function or `cancelIdleCallbackShim()`
*.if the browser doesn't support it.
* @param {!Function} callback
* @return {number}
*/
export const rIC = supportsRequestIdleCallback_ ?
requestIdleCallback : requestIdleCallbackShim;
/**
* The native `cancelIdleCallback()` function or `cancelIdleCallbackShim()`
* if the browser doesn't support it.
* @param {number} handle
*/
export const cIC = supportsRequestIdleCallback_ ?
cancelIdleCallback : cancelIdleCallbackShim;